Conventional automobile steering locks generally have the disadvantages described below.
1. Although an elongate tubular member and an elongate rod member are heat treated to have anti-sawing and anti-striking capabilities, the associated housing and lock with a copper key block are not possible to be heat treated. If the housing and the lock are sawn off, as shown in FIGS. 1 and 3 along line a--a, the anti-theft function of the device is totally lost.
2. Conventional locks for automobile steering lock devices are locked either by means of rotation or by pressing inward. The rotatable lock has a semi-circular dead bolt as shown in FIGS. 1 and 2, while the pressing lock has a rod-shaped dead bolt to extend in one of grooves in the rod member as shown in FIGS. 3 and 4. When the rod member combined with one of these locks receives an external strike or blow, a reactional shearing force is concentrated on the dead bolt and the groove so that the dead bolt may be broken as follows:
A. The rotatable semi-circular dead bolt as shown in FIGS. 1 and 2 turns away from the grooves of the rod member in an open condition, and turns to extend into one of the grooves in a locked condition. There is a hollow space C in the housing in which the dead bolt B moves. When the dead bolt B is broken, the space C gives the dead bolt B enough space to move either in the space C or in the groove D1. Either way it cannot stop the rod member from moving out of the housing A.
B. The pressing-inward dead bolt B as shown in FIGS. 3 and 4, extends vertically into one of the grooves D1 to lock the rod member D. When the dead bolt B is broken, it remains in the groove D1 and can be pulled, together with the rod member D, out of the housing A, thereby losing its locking function.